Texas Instruments LP2985A Schematic [ru]

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

−50 −25 0 25 50 75 100 125 150

VO= 3.3 V
C

byp

= 10 nF

Dropout − (V)

150 mA

50 mA

10 mA

1 mA

Temperature − ( C)°

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LP2985 150-mA Low-noise Low-dropout Regulator With Shutdown

1 Features 3 Description

1

• Output Tolerance of
– 1% (A Grade)
– 1.5% (Standard Grade)

• Ultra-Low Dropout, Typically
– 280 mV at Full Load of 150 mA
– 7 mV at 1 mA

• Wide VINRange: 16 V Max

• Low IQ: 850 μA at Full Load at 150 mA

• Shutdown Current: 0.01 μA Typ

• Low Noise: 30 μV

With 10-nF Bypass

RMS

Capacitor

• Stable With Low-ESR Capacitors, Including
Ceramic

• Overcurrent and Thermal Protection

• High Peak-Current Capability

• ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)

The LP2985 family of fixed-output, low-dropout
regulators offers exceptional, cost-effective
performance for both portable and nonportable
applications. Available in voltages of 1.8 V, 2.5 V, 2.8
V, 2.9 V, 3 V, 3.1 V, 3.3 V, 5 V, and 10 V, the family
has an output tolerance of 1% for the A version (1.5%
for the non-A version) and is capable of delivering
150-mA continuous load current. Standard regulator
features, such as overcurrent and overtemperature
protection, are included.

PART NUMBER PACKAGE BODY SIZE (NOM)

LP2985 SOT-23 (5) 2.90 mm x 1.60 mm
(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Dropout Voltage vs Temperature

LP2985

SLVS522O –JULY 2004–REVISED JANUARY 2015

Device Information

(1)

2 Applications

• Portable Devices

• Digital Cameras and Camcorders

• CD Players

• MP3 Players

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.

LP2985

SLVS522O –JULY 2004–REVISED JANUARY 2015

www.ti.com

Table of Contents

1 Features.................................................................. 1

2 Applications ........................................................... 1

3 Description............................................................. 1

4 Revision History..................................................... 2

5 Pin Configuration and Functions......................... 3

6 Specifications......................................................... 4

6.1 Absolute Maximum Ratings ..................................... 4

6.2 ESD Ratings.............................................................. 4

6.3 Recommended Operating Conditions...................... 4

6.4 Thermal Information.................................................. 4

6.5 Electrical Characteristics.......................................... 5

6.6 Typical Characteristics.............................................. 7

7 Detailed Description............................................ 11

7.1 Overview................................................................. 11

7.2 Functional Block Diagram ....................................... 11

7.3 Feature Description................................................. 11

7.4 Device Functional Modes........................................ 11

8 Application and Implementation ........................ 12

8.1 Application Information............................................ 12

9 Power Supply Recommendations...................... 16

10 Layout................................................................... 17

10.1 Layout Guidelines................................................. 17

10.2 Layout Example.................................................... 17

11 Device and Documentation Support................. 17

11.1 Trademarks........................................................... 17

11.2 Electrostatic Discharge Caution............................ 17

11.3 Glossary................................................................ 17

12 Mechanical, Packaging, and Orderable

Information........................................................... 17

4 Revision History

Changes from Revision N (June 2011) to Revision O Page

• Added Applications, Device Information table, Pin Functions table, ESD Ratings table, Thermal Information table,
Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply
Recommendations section, Layout section, Device and Documentation Support section, and Mechanical,

Packaging, and Orderable Information section. ..................................................................................................................... 1

• Deleted Ordering Information table. ....................................................................................................................................... 1

2 Submit Documentation Feedback Copyright © 2004–2015, Texas Instruments Incorporated

DBV (SOT-23) PACKAGE

(TOP VIEW)

1

2

3

5

4

V

IN

GND

ON/OFF

V

OUT

BYPASS

LP2985

www.ti.com

SLVS522O –JULY 2004–REVISED JANUARY 2015

5 Pin Configuration and Functions

Pin Functions

PIN

NAME NO.

BYPASS 4 I/O Attach a 10-nF capacitor to improve low-noise performance.
GND 2 — Ground
ON/OFF 3 I Active-low shutdown pin. Tie to VINif unused.
V

IN

V

OUT

1 I Supply input
5 O Voltage output

TYPE DESCRIPTION

Copyright © 2004–2015, Texas Instruments Incorporated Submit Documentation Feedback 3

LP2985

SLVS522O –JULY 2004–REVISED JANUARY 2015

www.ti.com

6 Specifications

6.1 Absolute Maximum Ratings

over virtual junction temperature range (unless otherwise noted)

V

IN

V

ON/ OFF

I

O

θ

JA

T

J

T

stg

Continuous input voltage range
ON/OFF input voltage range –0.3 16 V
Output voltage range

Output current

(3)

(4)

Package thermal impedance
Operating virtual junction temperature 150 °C
Storage temperature range –65 150 °C

(1) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings

only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating

Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) The PNP pass transistor has a parasitic diode connected between the input and output. This diode normally is reverse biased

(VIN> V
more details).

), but will be forward biased if the output voltage exceeds the input voltage by a diode drop (see Application Information for

OUT

(3) If load is returned to a negative power supply in a dual-supply system, the output must be diode clamped to GND.
(4) Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient

temperature is PD= (TJ(max) – TA)/θJA. Operating at the absolute maximum TJof 150°C can affect reliability.

(5) The package thermal impedance is calculated in accordance with JESD 51-7.

(2)

(4) (5)

(1)

MIN MAX UNIT

–0.3 16 V

–0.3 9 V

Internally limited

(short-circuit protected)

—

206 °C/W

6.2 ESD Ratings

VALUE UNIT

(1)

2000
1000

V

(ESD)

Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins

Electrostatic discharge V

Charged device model (CDM), per JEDEC specification JESD22-C101,

(2)

all pins

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

MIN MAX UNIT

V

IN

V

ON/ OFF

I

OUT

T

J

Supply input voltage 2.2
ON/OFF input voltage 0 V
Output current 150 mA
Virtual junction temperature –40 125 °C

(1) Recommended minimum VINis the greater of 2.5 V or V

+ rated dropout voltage (max) for operating IL.

OUT(max)

(1)

16 V

IN

6.4 Thermal Information

LP2985

THERMAL METRIC

R

θJA

Junction-to-ambient thermal resistance 206 °C/W

(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

(1)

DBV UNIT

5 PINS

V

4 Submit Documentation Feedback Copyright © 2004–2015, Texas Instruments Incorporated

LP2985

www.ti.com

6.5 Electrical Characteristics

at specified virtual junction temperature range, VIN= V
(unless otherwise noted)

PARAMETER TEST CONDITIONS T

IL= 1 mA 25°C –1 1 –1.5 1.5

ΔV

OUT

VIN– V

I

GND

V

ON/ OFF

I

ON/ OFF

Output voltage
tolerance

Line regulation VIN= [V

Dropout voltage

OUT

(1)

GND pin current μA

ON/OFF input voltage

ON/OFF input current μA

1 mA ≤ IL≤ 50 mA

1 mA ≤ IL≤ 150 mA

+ 1 V] to 16 V %/V

OUT(NOM)

IL= 0

IL= 1 mA

IL= 10 mA mV

IL= 50 mA

IL= 150 mA

IL= 0

IL= 1 mA 25°C (LP2985-10) 140 140

IL= 10 mA 25°C (LP2985-10) 250 250

IL= 50 mA 25°C (LP2985-10) 650 650

IL= 150 mA 25°C (LP2985-10) 1800 1800

V

< 0.3 V (OFF) 25°C 0.01 0.8 0.01 0.8

ON/ OFF

V

< 0.15 V (OFF)

ON/ OFF

V

= HIGH → O/P ON

ON/ OFF

(2)

V

= LOW → O/P OFF

ON/ OFF

V

= 0

ON/ OFF

V

= 5 V

ON/ OFF

SLVS522O –JULY 2004–REVISED JANUARY 2015

OUT(NOM)

+ 1 V, V

J

= 2 V, CIN= 1 μF, IL= 1 mA, C

ON/ OFF

LP2985A-xx LP2985-xx

MIN TYP MAX MIN TYP MAX

25°C –1.5 1.5 –2.5 2.5

–40°C to 125°C –2.5 2.5 –3.5 3.5 %V

25°C –2.5 2.5 –3 3

–40°C to 125°C –3.5 3.5 –4 4

25°C 0.007 0.014 0.007 0.014

–40°C to 125°C 0.032 0.032

25°C 1 3 1 3

–40°C to 125°C 5 5

25°C 7 10 7 10

–40°C to 125°C 15 15

25°C 40 60 40 60

–40°C to 125°C 90 90

25°C 120 150 120 150

–40°C to 125°C 225 225

25°C 280 350 280 350

–40°C to 125°C 575 575

25°C 65 95 65 95

25°C (LP2985-10) 125 125

–40°C to 125°C 125 125
–40°C to 125°C

(LP2985-10)

160 160

25°C 75 110 75 110

–40°C to 125°C 170 170

25°C 120 220 120 220

–40°C to 125°C 400 400

25°C 350 600 350 600

–40°C to 125°C 1000 1000

25°C 850 1500 850 1500

–40°C to 125°C 2500 2500

–40°C to 105°C 0.05 2 0.05 2
–40°C to 125°C 5 5

25°C 1.4 1.4

–40°C to 125°C 1.6 1.6

25°C 0.55 0.55

–40°C to 125°C 0.15 0.15

25°C 0.01 0.01

–40°C to 125°C –2 –2

25°C 5 5

–40°C to 125°C 15 15

OUT

= 4.7 μF

UNIT

NOM

V

(1) Dropout voltage is defined as the input-to-output differential at which the output voltage drops 100 mV below the value measured with a

1-V differential.

(2) The ON/OFF input must be driven properly for reliable operation (see Application Information).

Copyright © 2004–2015, Texas Instruments Incorporated Submit Documentation Feedback 5

LP2985

SLVS522O –JULY 2004–REVISED JANUARY 2015

Electrical Characteristics (continued)

at specified virtual junction temperature range, VIN= V
(unless otherwise noted)

PARAMETER TEST CONDITIONS T

V

n

ΔV

OUT

ΔV

IN

I

OUT(PK)

I

OUT(SC)

Output noise (RMS) C

/ f = 1kHz, C

Ripple rejection 25°C 45 45 dB
Peak output current V

Short-circuit current RL= 0 (steady state)

(3) See Figure 6 in Typical Performance Characteristics.

BW = 300 Hz to 50 kHz,

= 10 μF, 25°C 30 30 μV

OUT

C

= 10 nF

BYPASS

= 10 μF,

≥ V

OUT

= 10 nF

– 5% 25°C 350 350 mA

O(NOM)

(3)

C

BYPASS
OUT

OUT(NOM)

+ 1 V, V

J

= 2 V, CIN= 1 μF, IL= 1 mA, C

ON/ OFF

LP2985A-xx LP2985-xx

MIN TYP MAX MIN TYP MAX

OUT

25°C 400 400 mA

www.ti.com

= 4.7 μF

UNIT

6 Submit Documentation Feedback Copyright © 2004–2015, Texas Instruments Incorporated

200

220

240

260

280

300

320

0 0.5 1 1.5 2 2.5 3 3.5

Output Voltage − (V)

I

SC

− (mA)

VO= 3.3 V

−100

100 300 500 700

Time − (ms)

VI= 16 V
VO= 3.3 V
Ci= 1 mF
C

byp

= 0.01 mF

Short-Circuit Current −

(A)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

−500

0 500 1000 1500 2000

Time − (ms)

Short-Circuit Current −

(A)

VI= 6 V
VO= 3.3 V
Ci= 1 mF
C

byp

= 0.01 mF

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

−50 −25 0 25 50 75 100 125 150

VO= 3.3 V
C

byp

= 10 nF

Dropout − (V)

150 mA

50 mA

10 mA

1 mA

Temperature − ( C)°

9.85

9.90

9.95

10.00

10.05

10.10

10.15

10.20

-50 -25 0 25 50 75 100 125 150

Temperature – °C

Outp ut Voltage – V

VI= 11 V

VO= 10 V

CI= 1 µF

CO= 4.7 µF

IO= 1 mA

3.295

3.305

3.315

3.325

3.335

3.345

−50 −25

0 25 50 75 100 125 150

Output V

oltage − (V)

VI= 4.3 V
VO= 3.3 V
Ci= 1 mF
Co= 4.7 mF
IO= 1 mA

Temperature − ( C)°

LP2985

www.ti.com

6.6 Typical Characteristics

CIN= 1 μF, C

= 4.7 μF, VIN= V

OUT

OUT(NOM)

Figure 1. Output Voltage vs Temperature

SLVS522O –JULY 2004–REVISED JANUARY 2015

+ 1 V, TA= 25°C, ON/OFF pin tied to VIN(unless otherwise specified)

Figure 2. Output Voltage vs Temperature

Figure 3. Dropout Voltage vs Temperature

Copyright © 2004–2015, Texas Instruments Incorporated Submit Documentation Feedback 7

Figure 5. Short-circuit Current vs Time

Figure 4. Short-circuit Current vs Time

Figure 6. Short-circuit Current vs Output Voltage

0.001

0.01

0.1

1

10

10 100 1k 10k 100k 1M

Frequency − (Hz)

Ci= 1 mF
Co= 10 mF
VO= 3.3 V

10 mA

100 mA

1 mA

Output Impedance −

W( )

0

10

20

30

40

50

60

70

80

90

100

10 100 1k 10k 100k 1M

Frequency − (Hz)

Ripple Rejection − (dB)

VI= 5 V
VO= 3.3 V
Co= 4.7 mF
C

byp

= 10 nF

10 mA

100 mA

1 mA

0

10

20

30

40

50

60

70

80

90

100

10 100 1k 10k 100k 1M

Frequency − (Hz)

Ripple Rejection − (dB)

50 mA

150 mA

1 mA

VI= 3.7 V
VO= 3.3 V
Co= 10 mF
C

byp

= 0 nF

0

10

20

30

40

50

60

70

80

90

100

10 100 1k 10k 100k 1M

Frequency − (Hz)

Ripple Rejection − (dB)

VI= 5 V
VO= 3.3 V
Co= 4.7 mF
C

byp

= 10 nF

50 mA

150 mA

1 mA

0

10

20

30

40

50

60

70

80

90

100

10 100 1k 10k 100k 1M

Frequency − (Hz)

Ripple Rejection − (dB)

VI= 5 V
VO= 3.3 V
Co= 10 mF
C

byp

= 0 nF

50 mA

150 mA

1 mA

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

0

20 40 60 80 100 120 140

Load Current − mA

160

VO= 3.3 V
C

byp

= 10 nF

Ground Pin Current −

mA

LP2985

SLVS522O –JULY 2004–REVISED JANUARY 2015

Typical Characteristics (continued)

CIN= 1 μF, C

= 4.7 μF, VIN= V

OUT

OUT(NOM)

+ 1 V, TA= 25°C, ON/OFF pin tied to VIN(unless otherwise specified)

Figure 7. Ground Pin Current vs Load Current

www.ti.com

Figure 8. Ripple Rejection vs Frequency

Figure 9. Ripple Rejection vs Frequency Figure 10. Ripple Rejection vs Frequency

8 Submit Documentation Feedback Copyright © 2004–2015, Texas Instruments Incorporated

Figure 11. Ripple Rejection vs Frequency

Figure 12. Output Impedance vs Frequency

0

200

400

600

800

1000

1200

1400

−50 −25 0 25 50 75 100 125

150

Ground Current − (C)

0 mA

Temperature − (°C)

150 mA

50 mA

10 mA

1 mA

VO= 3.3 V
C

byp

= 10 nF

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 1 2 3 4 5 6

Input Voltage − (V)

Input Current − (mA)

RL= Open

RL= 3.3 kW

VO= 3.3 V
C

byp

= 10 nF

0.01

0.1

1

10

100 1k 10k 100k

Frequency − (Hz)

Noise Density −

( V/m

I

LOAD

= 1 mA

C

byp

= 1 nF

C

byp

= 10 nF

C

byp

= 100 pF

Hz)

0.001

0.01

0.1

1

10

10 100 1k 10k 100k

1M

Frequency − (Hz)

Ci= 1 mF
Co= 4.7 mF
VO= 3.3 V

10 mA

100 mA

1 mA

Output Impedance −

W( )

0.01

0.1

1

10

100 1k 10k 100k

Frequency − (Hz)

Noise Density −

m( V/

C

byp

= 1 nF

C

byp

= 10 nF

C

byp

= 100 pF

I

LOAD

= 150 mA

Hz)

LP2985

www.ti.com

Typical Characteristics (continued)

CIN= 1 μF, C

= 4.7 μF, VIN= V

OUT

OUT(NOM)

+ 1 V, TA= 25°C, ON/OFF pin tied to VIN(unless otherwise specified)

Figure 13. Output Impedance vs Frequency

SLVS522O –JULY 2004–REVISED JANUARY 2015

Figure 14. Output Noise Density vs Frequency

Figure 15. Output Noise Density vs Frequency

Copyright © 2004–2015, Texas Instruments Incorporated Submit Documentation Feedback 9

Figure 17. Ground-pin Current vs Temperature

Figure 16. Input Current vs Input Voltage

Figure 18. 2.2-μF Stable ESR Range

for Output Voltage ≤ 2.3 V